Joby GorillaPod Micro 800 Tripod. Probably the smallest useable tripod.

I didn’t buy this, just saw one at the store. Kind of impressed and think it would be a good choice for a bike tour. Joby also makes a smartphone clamp that attaches.

Folded Length: 3 1/2 inches
Load Capacity: 1.7 lbs
Weight: 2.3oz (65g)